Presentation Details

Room: Urano Date: 1 September Time: 11:30:00 Presenter: Riemer Vegter

Abstract Resume

Background:
Sprinting performance is a key aspect of wheelchair rugby, since accelerating faster then your opponent is essential to be free to catch the ball—preferably in the end zone. To improve
sprinting-ability individual measurement of sprint performance is a necessity. Therefore, during a season athletes are regularly tested on their physical capacity and sprint performance on a court is
usually one of them. However, not all biomechanically relevant parameters can be easily measured on a court, such as detailed measurement of power output and acceleration. On an instrumented
wheelchair ergometer this can be measured, while keeping the wheelchair-user combination unaltered. Moreover, since steering is not an issue, asymmetries between the left and right side can be
evaluated. In this abstract a comparison is made in sprint abilities between elite wheelchair rugby athletes of different classifications by performing a wheelchair sprint in their own wheelchair
rugby chair on an instrumented wheelchair ergometer over a court length of 28 m.
Methods:
18 Athlete’s of a National team performed an all out 15s sprint in their wheelchair-rugby chair on an instrumented wheelchair ergometer (VP100, France). The left and right roller are independently
capable of measuring force and the angle of rotation at 100 Hz. Custom written Matlab algorithms were used to analyze relevant biomechanical parameters. Asymmetry was defined as the difference between
the distance covered left and right when the best side reached 28m. Athlete’s were divided in a low-point (LP) (class 0-1.5, n=8) and high-point (HP) (class 2-3, n=10) group. T-tests were used to
compare the groups on relevant parameters.
Results:
On average high-point athletes had faster sprint times than low-point athletes (HP: 6.95s ± 0.89 & LP: 8.03s ± 0.68, p<0.01). This corresponded with a higher top-speed (HP: 4.8m/s ± 0.7 & LP: 4.1m/s ±
0. 5, p<0.05) and peak power output (HP: 667W ± 108 & LP: 357w ± 78, p<0.01). At the time the best player finished, the high-point players had covered a larger distance (HP: 22.9m ± 3.2 & LP: 18.9m ±
1.8, p<0.01). High point players did have more asymmetries between the left and right arm (HP: 2.0m ± 1.4 & LP: 0.7m ± 0.7, p<0.05).
Discussion:
The aim was to assess wheelchair-rugby athletes on their sprint performance. High-point players had faster sprint times over 28m, which they achieved by a higher power output leading to to higher
acceleration and consequently higher top speeds. Yet, high standard deviations show the heterogeneity within the two groups and some low point players were better than high-point players. This is in
line with the aim of classification to minimize the impact of impairments on sport performance. Probably training status, wheelchair fitting and total mass of the wheelchair-user combination also
contribute to sprinting on court. Surprisingly, more asymmetries were found in the high point group. Quantification of these asymmetries is important, since addressing them through training and/or
wheelchair fitting could lead to better performance.